338 DICKINSON AND OSBORNE: SPECIFIC HEAT OF ICE 



The platinum resistance coil (for use as a thermometer) em- 

 bedded in the calorimeter shows slight irregularities in its behav- 

 ior, probably due to the difference in expansion between the 

 platinum and the copper which surrounds it. Uncertainties on 

 this account, while in general negligible, can be avoided by- 

 measuring the temperature of the outer bath with a standard 

 resistance thermometer, using the thermo-couples to measure 

 the small difference, usually not more than a few thousandths 

 of a degree, between the calorimeter and the jacket. The 

 thermometer could probably be improved by changing the 

 construction. 



Results of a series of experiments give the constants of the 

 resistance thermometer and the heat capacity of the calorimeter 

 including a tin lined cell for use in determining the specific heat 

 of ice and water and the latent heat of fusion of ice. 



A series of check experiments on the specific heat of water 

 show the order of reproducibility of results, which can be ob- 

 tained with this calorimeter, to be 1 part in 2000. Measurements 

 made at temperatures between 0° and 40°C. gave results which 

 agree to within the limits of experimental accuracy with the 

 unpublished results of a long series of experiments made in the 

 usual form of stirred water calorimeter. The results are also in 

 satisfactory agreement with the most probable values deducible 

 from the data of the most careful investigations published by 

 other observers. 



PHYSICS. — The specific heat and heat of fusion of ice.^ H. C. 

 Dickinson and N. S. Osborne, Bureau of Standards. 



Results of previous determinations of the specific heat of ice 

 by certain observers have indicated a rapid increase in the 

 specific heat on approaching the melting point; whereas A. W. 

 Smith^ has found the heat capacity of ice to be practically con- 

 stant up to temperatures very close to zero, provided great care 

 and refinement are used to insure the purity of the ice, and that 



1 To appear in the Bulletin of the Bureau of Standards. 



2 Physical Review 17: 193. 1903. 



